Almost no one voted like this, since the vast majority of people who were old enough to vote in 1940 would have been dead by 2016.
If I had to describe someone, I'd say a 97 year old walking corpse from Vermont who's been senile for the past 15 years and accidentally checked the box for Hillary before dropping dead in the voting booth.
Well, describe a voter demographic like this; not necessarily fan individual voter.
Possibly ancestral Republicans in wealthy New England towns?
Orange County, California is not New England. What Voter Demographic defection in Orange County, California caused the County to vote like this?
Well, clearly a decent amount of college educated whites defected to Hillary, but the bigger reason that it's becoming much more Democratic is because it's rapidly diversifying.
Additionally, the guy who was a young, educated professional with a good job back in the 1970s in Orange County is likely one of the staunchest Republicans in the area, haha. "This isn't MY Orange County," if you will.
On the other hand though, a 13% swing in 4 years, especially in such a populated county, can not be solely explained away by "demographics".